[Anu_Ud]

Hi,
My RAV4 is extremely hard to start when warm. It's a RAV4 manufactured in Japan in 1995. Below are the details.

Engine: 3S-FE
Frame number: SXA-11

When I check the engine bay vacuum lines, I found that the fuel pressure regulator is connected directly without connecting through the default lines which runs below the inlet manifold. Could this be the cause for hard start when the engine is warm (does the heat of the engine has any effect to make the warm start easy when running through the default vacuum lines below the inlet manifold?)
Also I noticed that, it's missing the vacuum switching valve (VSV) shown on the diagram below. Does anyone know what is the purpose of the VSV. Could that be the reason for the issue?

Thank you very much!
Anu

 

[LugNut]

Describe "hard to start."

If "just" a longer cranking time, I would suspect vapor-lock. If the fuel return function is disabled, then that could be the cause.

But also do a major tune up, including replacing the air filter and maybe the fuel filter. And also try opening the fuel cap before your hot-starts to see if there is a venting problem.

 

[Anu_Ud]

Describe "hard to start."

If "just" a longer cranking time, I would suspect vapor-lock. If the fuel return function is disabled, then that could be the cause.

But also do a major tune up, including replacing the air filter and maybe the fuel filter. And also try opening the fuel cap before your hot-starts to see if there is a venting problem.

Hi,
Thank you very much for replying. I will check what you have mentioned on your message and let you know.

Do you have any idea about the VSV (vacuum switching valve) which is located in between the intake manifold and fuel pressure regulator?

 

[LugNut]

The Factory Service Manual will show its use.

There is another very similar VSV on the back of the 3S-FE that is part of the EGR system. Experience says to only use Aisin-brand part (or OE) when replacing it.